Play-free guide rollers for continuous casting mould

ABSTRACT

A continuous casting plant for slabs comprising a lifting table to be oscillated in vertical direction, a water-cooled casting mould releasably connected to said lifting table, and a short, vertical bar guiding means arranged below said casting mould, wherein said lifting table is designed as a rectangular, closed, water-cooled, box-type frame having two vertical ledges arranged on its two narrow sides, said ledges engaging with guiding means supported on the pouring platform and adjustable to be exactly vertical. By this guiding mechanism any displacements between the casting mould and the bar guiding means are safely eliminated and cracks in the bar are avoided.

United States Patent PLAY-FREE GUIDE ROLLERS FOR CONTINUOUS CASTING MOULD 5 Claims, 3 Drawing Figs.

US. Cl 164/260, 164/283,193/35 R Int. Cl B22d 11/02, B22d 27/08 Field of Search 164/260,

[56] References Cited Primary ExaminerRobert D. Baldwin Att0rneyBrumbaugh, Graves, Donohue and Raymond ABSTRACT: A continuous casting plant for slabs comprising a lifting table to be oscillated in vertical direction, a watercooled casting mould releasably connected to said lifting table, and a short, vertical bar guiding means arranged below said casting mould, wherein said lifting table is designed as a rectangular, closed, water-cooled, box-type frame having two vertical ledges arranged on its two narrow sides, said ledges engaging with guiding means supported on the pouring platform and adjustable to be exactly vertical. By this guiding mechanism any displacements between the casting mould and the bar guiding means are safely eliminated and cracks in the bar are avoided.

PATENTED um 1 2 I971 SHEET l'UF 3 IIINVENTOR. RUDOLF SCHOFFMANN Maw his ATTORNEYS.

PLAY-FREE GUIDE ROLLERS FOR CONTINUOUS CASTING MOULD The invention relates to a continuous casting plant for slabs comprising a water-cooled casting mould which is releasably connected to a vertically movable lifting table so that the mould may be caused to oscillate, and a short, vertical bar guiding means arranged below the casting mould.

It has been found that in continuous casting plants in which slabs with large cross sections are produced, e.g. slabs which are 1,000 to 2,000 mm. broad and 150 to 300 mm. thick, already small dsplacements of e.g. 0.2 mm. between the wall of the casting mould and the vertical bar guiding means which is arranged below the mould lead to difiiculties, i.e. to cracks in the drawn bar. Since continuous casting moulds are oscillating in vertical direction during casting, the driving mechanism with which the oscillations are produced and the guiding mechanism of the casting mould ought to meet the highest demands so that such displacements may be avoided. For various reasons this has been impossible so far. One of the reasons has been the difference in temperature betweenthe casting mould and the lifting table which is actuated by the driving mechanism producing the oscillatory movements. The lifting table is heated by the radiation of the cast bar leaving the casting mould as well as by steel and slag splashes and therefore has a higher temperature than the water-cooled casting mould; this uneven heating results in an expansion and warping of the lifting table. These difficulties are particularly severe with large lifting tables for continuous casting moulds for slabs. The external dimensions of such lifting tables amount to about l.5 3.5 m. The guiding means of the lifting table which is moving in vertical direction have had to be provided with a certain play in order to avoid jamming. However, such guiding means with play lead to a shaky travel of the lifting table, and the displacements between the mould wall and the stationary bar guides arranged below the mould grow to an extent to cause cracks in the bar, a disadvantage that has already been mentioned.

The invention is aimed at avoiding the described disadvantages and difficulties by creating a continuous casting plant for slabs in which an excellent oscillation of the mould and the lifting table, respectively, is obtained, and in which, at the same time, any displacements in relation to the adjoining vertical bar guiding means and secondary cooling zone are avoided. This aim of the invention is achieved in a plant of the kind defined in the introduction, in that the lifting table is formed as a rectangular, closed, water-cooled, box-type frame which preferably in the middle of each of its narrow sides is provided with a vertical ledge engaging into guiding means fixed to the pouring platform and adjustable to be exactly vertical.

Preferably, each ledge is guided without play on its three free sides by two pairs of rollers arranged one above the other and by a further roller arranged perpendicularly in relation to said pairs of rollers.

Advantageously, each two pairs of rollers and the rollers arranged perpendicularly to the pairs of rollers are arranged in common housing fixed to said pouring platform.

According to a preferred embodiment of the invention rapid connections for the supply of cooling water are provided between the frame and the mould, said rapid connections being formed by bushings of the frame and hollow pins of the mould.

Advantageously, the inner cross section of the frame is greater than the outer dimensions of the vertical bar guiding means arranged below the casting mould so as to permit the insertion and removal of the bar guiding means in vertical direction after the mould has been released from the frame.

In order that the invention may be more fully understood an embodiment thereof shall now be explained with reference to the accompanying drawings, in which FIG. 1 is a vertical sectional view of a lifting table or frame according to the invention, along the line [-1 of FIG. 2.

FIG. 2 is the ground plan for FIG. 1.

FIG. 3 is a vertical sectional view along the line lll-lll of FIG. 2, and in FIG. 3 also the lifting device is shown.

In FIG. 1 numeral 1 denotes the casting mould whichis indicated in broken lines. The mould is releasably connected to the lifting table by means of keyed joints 3, 4, 5, 6 which may easily be released; the lifting table has the form of an oblong, closed frame 2 and is water-cooled. The frame 2 comprises supply ducts 7, 8, 9, l0 and drains l1, 12 for the cooling water. Between the frame 2 and the mould 1 there are rapid connections 13, l4, 15, 16 which are formed by bushings in the frame 2 and hollow pins on the mould 1. Further rapid connections 17, 18 are provided for the outflow of water flowing through conduits installed in the frame but not shown in the drawing. Owing to these provisions the mould l and the frame 2 are uniformly and effectively cooled so that no distortions will occur as a result of differential heat influences, and favorable conditions are created for an exact and accurate guiding of the frame.

Levers 19, 20 act upon the narrow sides of the frame 2. These levers are articulated to a lifting and shifting device 30 by means ofejoumals 22 and rods 28 so that the frame 2 is oscillated when the rotatory movement of the eccentric disc 35 is transferred to the frame via the crankshaft 34 in the direction indicated by the double arrow (FIG. 3). By means of trunnions 21 the levers 19, 20 are hingedly connected to angle levers 24 which are pivotable around a common-connection shaft 23. Furthermore, the angle levers 24 are fixed to 'a baseplate 27 via an articulately mounted prestressed spring member 26. Numeral 25 denotes a further baseplate for the connection shaft 23. Regarded at greater detail, the lifting and shifting device 30 comprises a spindle 31, a nut 31' and a driving motor 32. This driving motor serves to move the spindle 31 and to shift the nut 31 towards the right-hand side so that the crankshaft 34 which is hingedly connected to the nut 31' assumes the position 34' which is indicated in broken lines. This position corresponds to the lift minimum. Numeral 29 denotes a connection shaft and numerals 33 and 36 denote baseplates.

According to the invention the frame 2 is guided by means of two ledges 37, 38 which are arranged on the narrow sides of the frame 2 and are each engaged on two sides by pairs of rollers 41, 42; 43, 44 and 45, 46; 47, 48, respectively. The ledges 37,38 are very narrow so that even the smallest expansions caused by heate.g. by changes of the cooling water temperature-cannot affect the precision of the lifting movement. For absorbing the lateral forces which may act upon the mould through the bar, rollers 49,50 are provided which are arranged perpendicularly to the above-mentioned pairs of rollers to engage the ledges 37,38; the ledges are thus guided by rollers from three sides. All rollers may be reset so that despite the fact that the ledges 37,38 will be worn the frame will always be accurately guided. The rollers are mounted in sheet housings 51,52 which are connected to the steel construction 53 of the pouring platform or supported by crosspieces 54,55. The ledges 37,38 are fixed to the bearing plates 39.40 which in turn are releasably connected with the frame 2 so as to permit the exchange of worn ledges.

What 1 claim is:

l. A continuous casting apparatus for slabs comprising a lifting table arranged on a pouring platform said guiding means for each ledge comprising a set of adjustable rollers for play-free engagement of said ledge on its three free sides in a vertical direction, a water-cooled casting mould releasably connected to said lifting table, said lifling table being designed as a rectangular, closed, water-cooled, box-type frame having oppositely disposed vertical ledges mounted in engagement with guiding means supported on said pouring platform and adjustable to be exactly vertical said guiding means for each ledge comprising a set of adjustable rollers for play-free engagement of said ledge on its three free sides.

2. The apparatus of claim 1, in which one of said ledges is arranged in the middle of each narrow side of said rectangular frame.

enclosed in a housing supported on said pouring platform.

5. The apparatus of claim 1, in which rapid connections for the supply of cooling water are provided between said frame and said mould.

5 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,612,156 Dated October 12, 1971 Inventor(s) Rudolf Schoffmann It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, lines 62-64, delete said guiding means for each ledge comprising a set of adjustable rollers for play-free engagement of said ledge on its three free sides" and insert means for oscillating said table--; and

Col. 2 line 70, after "vertical" insert a comma.

Signed and sealed this 21 st day of March 1972.

(SEAL) Attest:

EDWARD M.F'LETCHER,JR. ROBERT GOT'I'SCHALK Attesting Officer Commissioner of Patents 

1. A continuous casting apparatus for slabs comprising a lifting table arranged on a pouring platform said guiding means for each ledge comprising a set of adjustable rollers for play-free engagement of said ledge on its three free sides in a vertical direction, a water-cooled casting mould releasably connected to said lifting table, said lifting table being designed as a rectangular, closed, water-cooled, box-type frame having oppositely disposed vertical ledges mounted in engagement with guiding means supported on said pouring platform and adjustable to be exactly vertical said guiding means for each ledge comprising a set of adjustable rollers for play-free engagement of said ledge on its three free sides.
 2. The apparatus of claim 1, in which one of said ledges is arranged in the middle of each narrow side of said rectangular frame.
 3. The apparatus of claim 1, in which each ledge has a substantially square cross section and is guided without play on its three free sides by two pairs of rollers arranged one above the other and by a further roller arranged perpendicularly in relation to said pairs of rollers.
 4. The apparatus of claim 1, in which each set of rollers are enclosed in a housing supported on said pouring platform.
 5. The apparatus of claim 1, in which rapid connections for the supply of cooling water are provided between said frame and said mould. 